| 摘要 |
<p>PURPOSE:To control oxidization deterioration of coating generated by sand and earth under the high temperature embedding by coating the outer surface of a basetreated steel pipe with modified polyolefin containing a specified component and polyolefin. CONSTITUTION:Modified polyolefin 4 containing phosphoric acid 2,2'-methylene- bis(4,6-di-tert-butylphenol)sodium as an essential component and polyolefin 5 are laminated successively on the outer surface of a base treated steel pipe 1. As for polyolefin, polyethylene, polypropylene, polybutane, or a copolymer of (alpha-olefin such as ethylene and propylene, 1-butene, 1-hexene, 4-methyl-1- bentene, 1-octane or the like is used, and as for modified polyolefin, bonding polyolefin which is polyolefin modified by unsaturated carboxylic acid or its anhydride is used. In that case, as the base treatment of the steel pipe chromate treatment 2 is applied on the outer surface of the steel pipe, and then epoxy primer treatment 3 is applied.</p> |
